Possibility of re-screening intervals of more than one year in men with PSA levels of 4.0 ng/ml or less

Background: The optimal re-screening interval is one of the most important issues to evaluate the effectiveness of screening for prostate cancer.

Methods: Between 1992 and 2000, 7,026 men aged 50-78 with baseline PSA levels of 4.0 ng/ml or lower underwent screening for prostate cancer twice or more. The risk of developing prostate cancer relative to elapsed years and baseline PSA levels were investigated.

Results: Prostate cancer was detected in a total of 127 cases (1.8%). The detection rate of prostate cancer was high between 1.6% and 5.5% at 1 year after baseline PSA measurements in men with baseline PSA levels of 2.1-4.0 ng/ml. In men with baseline PSA levels of 1.1- 2.0 ng/ml, the detection rate increased from 0.06% to 1.02% with passed years. The proportion of stage >/=T3 was high at 63% in prostate cancer cases detected between 3 and 4 years after baseline PSA levels being 1.1-2.0 ng/ml. In men with baseline PSA levels of 1.0 or lower, the cumulative detection rate of prostate cancer was low at 0.01% within 3 years, however, the detection rate increased to 0.34% after 5 or more years from baseline PSA measurements.

Conclusions: The re-screening interval was recommended to be 1, 1-2, and 3-5 years for men with baseline PSA levels of 2.1-4.0 ng/ml, 1.1-2.0 ng/ml, and 1.0 ng/ml or lower, respectively.